1. Field of the Invention
The present invention relates to cosmetic powders comprising an N-mono long chain acyl basic amino acid and a particular α-aminolactam derivative. The present invention also relates to cosmetic compositions containing such a powder.
2. Discussion of the Background
As cosmetic compositions containing a cosmetic powder as a main ingredient, makeup products such as foundations, face powders, pressed powders, blushers, eyeliners and eyebrow liners; body care products such as body powders and baby powders; and the like are commercially available. The cosmetic powder is required to exhibit properties such as superior spreadability on and superior affinity to the slin upon application, maintenance of high lightness and high moisture of the skin after application, which prevents easy occurrence of makeup deterioration, and the like.
As a method of preventing makeup deterioration, it has been proposed to perform a surface treatment on various cosmetic particles using a fluorine compound so as to impart water repellency and oil repellency (see, JP-A-55-167209, JP-A-62-250074, JP-A-1-180811, and U.S. Pat. No. 3,632,744). However, the obtained cosmetic powder is defective in that the spreadability on the skin upon application is generally degraded and the lightness and moisture of the skin is strikingly lost after application, as compared to a cosmetic powder free of the treatment with a fluorine compound.
Also, there has been proposed a method of compounding an N-mono long chain acyl basic amino acid as a cosmetic powder and a method of improving texture of another powder or imparting a hydrophobic property on a hydrophilic surface with the use of an N-mono long chain acyl basic amino acid as a surface treatment agent (see, JP-A-61-10503). Although the N-mono long chain acyl basic amino acid is superior in spreadability on the skin upon application, it is pointed out to be defective in that, due to poor oil repellency, the lightness and moisture of the skin decreases after application, and the like.
Accordingly, it has been proposed to improve the lightness and moisture of the skin after application and to prevent makeup deterioration by performing a surface treatment on various cosmetic powders using an acyl basic amino acid and ester phosphate having a specific perfluoroalkyl group (see, JP-A-5-339126). However, the lightness and moisture of the skin after application remains unsatisfactory, and what is worse, the use of a halogen compound gave rise to a new environmental problem.
Thus, there remains a need for cosmetic powders which do not suffer from the above-described drawbacks. There also remains a need for cosmetic compositions which contain such a powder.